Add table of contents to FAST-DNA README.md

[Falkicon]

What is your feature request? Please describe.
Add a table of contents to the repository README.md.

Describe the solution you'd like
Example from another README:

Describe alternatives you've considered
There is a collapsible variation:

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.